Different types of containers and dispensers for the distribution of material are known within the packaging industry. One example is described in U.S. Pat. No. 3,759,259 issued Sep. 18, 1973 to Andrew Truhan. The Truhan patent discloses a combination applicator and container for medicinal substances. The applicator includes a holder and a fibrous wadding of cotton. The container has flexible walls and a flat seal that spans the container opening. The flat seal is heat sealed to the interior surface of the container. The flat seal is perpendicular to the flexible walls and ruptures upon the application of inward force to the container side walls. In another embodiment, the flat seal includes one or more score lines which form lines of weakness or burst lines when an inward force F is applied to the container side walls.
U.S. Pat. No. 3,684,136 to Baumann discloses a receptacle for receiving and mixing liquid and/or solid substances. The receptacle includes a lower mixing chamber M, an upper secondary chamber S, and a foil dividing wall. The lower surface of dividing wall is convex and the top surface of the wall is concave. In the first embodiment, the surface of the dividing wall features a scored notch(es), that signifies a weakened portion of the dividing wall. The notches can be arranged in a star or cross orientation. To tear the dividing wall, lateral pressure P is applied to receptacle walls adjacent to the dividing wall. When lateral pressure P is terminated, the dividing wall returns to its original shape and the opening will close. In the second embodiment, the receptacle includes outer projections which indicate the direction in which the notches should be disposed during assembly.
In both Truhan and Baumann, the seal separating the chambers has score lines which are formed from the removal of material from the seal itself. The removal of material is necessary to sufficiently weaken the seal structure to facilitate rupture. However, the removal of material compromises the burst strength of the seal and can lead to inconsistent and untimely seal rupture. As a result, the effectiveness of both the seal and the device is reduced.
Furthermore, with both devices it is necessary to under fill the container with liquid leaving ample air space. This under filling increases the chance of accidental seal rupture from pressure on the container. Consequently, the volume of liquid stored within the chamber must be reduced.
Lastly, the dispensers disclosed in Truhan and Baumann are designed to release the entire fluid contents at one time. Thus, the user cannot control the distribution and application of the liquid over a period of time.
The present invention is provided to solve these and other problems.